Transient Flow Modelling of Start-up CO2 Injection into Highly-Depleted Oil/Gas Fields

Abstract

Abstract-Carbon Capture and Storage (CCS) represent a promising technology in mitigating global warming challenges. In this study, we developed a model for the numerical simulation of the highly transient phenomena taking place in a wellbore during start-up CO 2 injection operations. The basic conservation equations are considered in the tubing. The wall friction factor and heat transfer coefficient between the fluid and the surrounding formation are also taken into account. The simulation results obtained show a significant drop in pressure and temperature at the wellhead during CO 2 start-up injection. This is a serious safety concern and poses several risks, including hydrate and ice formation with interstitial water around the wellbore and thermal shocking of the wellbore casing steel and thus in response, ways of minimising its occurrence are recommended.

Investigating the impact of flow rate ramp-up on carbon dioxide start-up injection

“…Xiaojiang Li et al, (2017) presented a unified model for wellbore flow and heat transfer in pure CO2 injection for geological sequestration, EOR and fracturing operations. Also recently, Samuel & Mahgerefteh, (2017) published a paper on transient flow modelling of the start-up injection process without ramp-up. The study shows the consequent effect of quasi-adiabatic Joule-Thomson expansion when high pressure CO2 is injected into a low pressure injection well.…”